What criteria should I use to determine when to refer a patient with hypertrophic cardiomyopathy to a cardiologist?

Referral of a patient with hypertrophic cardiomyopathy (HCM) to a cardiologist should be considered when there are clinical features or diagnostic findings suggestive of increased risk or complications. Key criteria include the presence of symptoms such as syncope or presyncope, particularly if unexplained by other causes, as these may indicate ventricular arrhythmias or obstruction requiring specialist assessment NICE CKS. Palpitations precipitated by exercise, a family history of sudden cardiac death under 40 years, or documented arrhythmias such as ventricular tachycardia or frequent ventricular extrasystoles also warrant cardiology referral NICE CKS.

Additionally, patients with evidence of left ventricular outflow tract obstruction, especially midventricular obstruction, or those with reduced left ventricular ejection fraction (≤35%) should be referred for specialist evaluation to consider advanced therapies including implantable cardioverter defibrillators (ICDs) or cardiac resynchronization therapy NICE CKS Cecchi et al. 2006. Echocardiographic findings of moderate to severe hypertrophy or obstruction, or symptoms of heart failure, angina, or breathlessness related to HCM, further support the need for specialist input NICE CKS.

Urgent referral is indicated if there is exertional syncope or severe symptoms such as angina or breathlessness on minimal exertion, as these may reflect significant obstruction or arrhythmic risk NICE CKS. Routine referral is appropriate for patients with abnormal ECG findings, recurrent sustained tachyarrhythmias, or a history of paroxysmal supraventricular tachycardia in the context of HCM NICE CKS.

In summary, referral to a cardiologist for patients with hypertrophic cardiomyopathy should be based on symptomatic presentation (syncope, presyncope, exertional symptoms), arrhythmic risk factors (family history of sudden cardiac death, documented ventricular arrhythmias), echocardiographic evidence of obstruction or significant hypertrophy, and reduced ejection fraction to enable specialist assessment and management NICE CKS,NICE CKS Cecchi et al. 2006.